This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This study will assess whether Dehydroepiandrosterone (DHEA) supplementation enhances memory and visual perception. 192 healthy women subjects(ages 55-65/70-80) (BMI>35) will be randomized into either DHEA treatment or placebo for 4 weeks and then crossed over. A battery of parameters will be performed during each period and results correlate with hormonal levels. The tests performed include two cognitive domains --- episodic memory and visual spatial processing. The authors use classic theoretical descriptions of a task in each domain --- recognition memory for episodic memory and mental rotation for visual spatial processing--- to identify elementary cognitive processes that may be mediating the effects of sex steroids. Appropriate serum hormones will also be determined. Specific Aim 1: Identify the effects of sex steroids on elementary cognitive processes mediating recognition memory and mental rotation in post-menopausal women. Specific Aim 2: Determine whether DHEA administration influences cognitive performance on a range of heretofore unexamined tasks in post-menopausal women.